The present invention relates to a mixture for application on an animal to provide an essentially non-evaporative, non-absorbent and not water soluble barrier protection against the negative effects of external pests. The present invention also relates to a method of protecting animals using such a mixture.
For application to animals, it is known to blend active ingredients such as insecticides, ectoparasitides and endoparasitides with oil or water based carriers. These carriers have a low viscosity, based on cost and in particular the ability of such a carrier to penetrate below the hair of an animal.
The carriers of heretofore known mixtures have a viscosity that allows the carrier to penetrate below the animal's hair since many active ingredients degrade substantially in UV light and therefore lose their efficacy relatively quickly. By using a low viscosity oil or water, the known products will penetrate under the surface hair of the animal and will thus reside on the animal out of the sunlight, with the animal's hair shading the product. This extends the life of the active ingredient on the animal. A low viscosity oil or water, once applied and below the surface hair and on the skin of the animal, also enables the spread of the oil to increase the surface area of the animal being covered by the active ingredient. While low viscosity improves the spread of these products, negatively they are very susceptible to mechanical water migration and/or they wash off in either rain storms or when water dosing of animals is implemented for animal cooling or cleaning purposes.
An additional disadvantage of low viscosity oils is in their inherent low weight or mass. Because of this, when applied through sprayers or equipment such as that described in U.S. Pat. No. 6,230,660, they are inherently susceptible to even slight wind currents. When wind is present as the host animal is sprayed, much or all of the discharged mixture may be lost to the atmosphere as a result of wind currents and fail to be applied to the host animal in proper amount or even at all. This results in either or both increased usage of the applied mixture, which is economically inefficient, and/or insufficient application of the mixture to the animal, in which case intended results may be substandard or even nonexistent.
Typically these products have been and are designed and manufactured for the treatment of horn flies, stable flies, ticks and other external blood sucking pests, where ½ to 5 ounces of product is dispensed every 2 to 6 weeks along the center of the back from the tail head to the shoulders. This volume of product is sufficient to overcome losses to follicle and dermal absorption and half-life or other degradation of the active ingredients, the remainder then resting on the skin below the hair line where the above mentioned pests would come in contact with it during feeding.
A drawback of the heretofore known carriers is that they are not optimally effective in making the active ingredient available for the required contact with all pests of concern. An example of this would be house flies that are non blood sucking and feed, for example, on debris upon animals or upon sites upon the animal where saliva or mucous are present and secreted such as the eyes, nostrils, mouth, and vulva. Furthermore, this allows transdermal absorption of the active ingredient into the animal and hence possibly its entry into the human food chain.
Examples of heretofore known compositions include U.S. Pat. Nos. 5,134,132 (Matthewson), 4,762,718 (Marks Sr.), 6,071,857 (Vogt et al.), 4,668,666 (Allan et al.) and 4,568,541 (Dorn et al). Further known compositions are described in U.S. Pat. Nos. 6,001,384 (Jeannin) and 6,524,594 (Santora), and U.S. Pat. No. 2002/00 34489 (Weigland). Unfortunately, Jeannin, as do several of the other earlier patents, operate systemically, thus potentially adversely affecting the quality of any derived human or pet food product. Furthermore, among others, Vogt, Santora and Weigland contain surfactants or emulsifiers, which make them absorbable and/or water soluble, and thus subject to the aforementioned drawbacks. Additionally, since surfactants by their very nature lower the surface tension of the solution in which they are incorporated, their presence greatly increases the potential for transdermal absorption into the treated animal and, therefore, the potential for the active ingredient to enter the food chain of either humans or other animals.
It is therefore an object of the present invention to provide an effective animal barrier protection mixture that remains on surface relatively unaffected by follicle and dermal penetration or absorption and resistant to mechanical water migration.